Test Code RBCS Relative B-Cell Subset Analysis Percentage, Blood
Useful For
Screening for humoral or combined immunodeficiencies, including common variable immunodeficiency, hyper IgM syndrome, among others, where B-cell subset distribution information is desired
Assessing B-cell subset reconstitution after hematopoietic cell or bone marrow transplant
Assessing B-cell subset reconstitution following recovery of B cells after B-cell-depleting immunotherapy
This test is not indicated for the evaluation of lymphoproliferative disorders (eg, leukemia, lymphoma, multiple myeloma).
This test should not be used to monitor B-cell counts to assess B-cell depletion in patients on B-cell-depleting therapies.
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
CVID | CVID Confirmation Flow Panel | Yes | No |
Testing Algorithm
This test should be ordered only when percentages (relative distribution of B cell subsets within the total B-cell population) are needed for the reportable B-cell subsets. If both percentages and absolute counts are needed for the reportable B-cell subsets, order IABCS / B-Cell Phenotyping Profile for Immunodeficiency and Immune Competence Assessment, Blood.
Method Name
Fluorescent Flow Cytometry
Reporting Name
Relative B Cell Subset Analysis %Specimen Type
Whole Blood EDTAOrdering Guidance
This test should be ordered only when percentages are needed for the reportable B-cell subsets. If both percentages and absolute counts are needed for the reportable B-cell subsets, order IABCS / B-Cell Phenotyping Profile for Immunodeficiency and Immune Competence Assessment, Blood.
Shipping Instructions
Specimens are required to be received in the laboratory on weekdays and by 4 p.m. on Friday. No weekend processing. Collect and package specimens as close to shipping time as possible. Ship specimens overnight.
It is recommended that specimens arrive within 24 hours of collection.
Necessary Information
Ordering physician's name and phone number are required.
Specimen Required
Specimen Type: Whole blood
Container/Tube: Lavender top (EDTA)
Specimen Volume:
≤14 years of age: 4 mL
>14 years of age: 10 mL
Collection Instructions:
1. Send whole blood specimen in original tube. Do not aliquot.
2. Label specimen as blood for RBCS / Relative B Cell Subset Analysis Percentage, Blood.
Additional Information: For serial monitoring, it is recommended that specimens are collected at the same time of day.
Specimen Minimum Volume
≤14 years of age: 3 mL; >14 years of age: 5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole Blood EDTA | Refrigerated | 48 hours | PURPLE OR PINK TOP/EDTA |
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | Reject |
Reference Values
The appropriate age-related reference values will be provided on the report.
Day(s) Performed
Monday through Friday
Report Available
3 daysPerforming Laboratory

Test Classification
This test was developed using an analyte specific reagent. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
86356 x7
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
RBCS | Relative B Cell Subset Analysis % | 90416-9 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
BCD19 | CD19+ % of total Lymphocytes | 8117-4 |
BCD20 | CD20+ % of total Lymphocytes | 8119-0 |
BCD27 | CD27+ % of CD19+ B Cells | 89358-6 |
B27MD | CD27+ IgM+ IgD+ % of CD19+ B Cells | 89352-9 |
B27N | CD27+ IgM- IgD- % of CD19+ B Cells | 89350-3 |
B27M | CD27+ IgM+ IgD- % of CD19+ B Cells | 89348-7 |
BIGM | IgM+ % of CD19+ B Cells | 89346-1 |
B38MN | CD38+ IgM- % of CD19+ B Cells | 89344-6 |
B38MP | CD38+ IgM+ % of CD19+ B Cells | 89341-2 |
B21P | CD21+ % of CD19+ B Cells | 89356-0 |
B21N | CD21- % of CD19+ B Cells | 89355-2 |
RBCSI | Interpretation | 69048-7 |